Find the install directory of the game. If there was an ingame crash, there should be a 'log.txt' file, send that to me jay@murudai.com. Try playing the game through terminal too, then send the output to that email.

When you run the game through terminal, does the Steam Overlay still show up? If the overlay doesn't show up when it works, then it could be an issue with that. A bunch of games have been having issues with the Steam Overlay (including this one), and that's just due to Linux Steam still being in Beta.